An Approach to Addressing Interactive Effects of Multiple Hydro Projects in a River Basin

Abstract: Cumulative effects issues continue to arise, not only related to multiple small hydro projects, but also to multiple relicensing of major projects, development of multiple projects at existing structures, and additional proposals in highly-developed basins where operations of several existing projects might change significantly in the presence of a new project. To meet these assessment needs, no single 'cumulative effects methodology' will probably suffice. Instead, it will be necessary to develop an overall assessment framework based on knowledge of 1) how multiple projects of different kinds behave in a river basin and 2) how resources are likely to respond to that project behavior. The key to dealing with these two points is some understanding of how multiple projects of various kinds interact among themselves, and with the affected resources.